Preparation and Properties of Tetrapyrrole Photosensitizer Loaded Magnetic Nanocomposites
(0) Photodynamic therapy (PDT) is an emerging modality for the treatment of a variety of diseases 1-3. The objective of this work was to develop a photodynamic drug nanocomposites consisting of magnetite and drug with SiO2 shell by sol-gel method. PDT drug combined with magnetic nanoparticles offers an effective and selective method for destroying diseased tissues without damaging adjacent healthy ones. SiO2 was chosen as the shell as it has a number of advantages over organic polymeric particles as widely known, such as the stable quality and biocompatibility etc 4-5. The nanocomposites were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD). A TEM image of the nanocomposites is shown in Figure 1. The nanocomposites are approximately spherical, sized in the range of 30-50 nm. It clearly indicates the existence of drug in the nanocomposites by comparison between their FT-IR spectra. The silica layer is amorphous as indicated by the broad SiO2 peak identified in the X-ray patterns. From the observation of the UV-vis spectra, it approved that the drug was enwrapped in the nanocomposites. The generation of singlet oxygen was measured by using N, N-Dimethyl-4-nitrosoaniline (RNO) as a selective scavenger. Using the laser light to irradiate the nanocomposites and RNO system, the decrease at 440 nm (λmax) of RNO revealed the resulting of 1O2 from the nanocomposites. Figure 2 shows the UV-vis absorption spectra of the mixture of the nanocomposites and RNO as a function of irradiation time. It clearly indicated that the photo-sensitizer was working normally.
Fe3O4 SiO2 PDT Nanocomposites Singlet oxygen
刘付现 倪似愚 陈志龙 周兴平 王寅生
东华大学生物科学与技术研究所 人民北路2999号,中国上海201620
国际会议
成都
英文
2007-11-19（万方平台首次上网日期，不代表论文的发表时间）